Compressors are widely used in gas turbines, jet engines, and various other industrial applications. A typical compressor includes multiple stages of aerofoils to progressively compress the working fluid. The multiple stages of aerofoils include rotating aerofoils, also known as blades or rotors, to accelerate the working fluid. Stationary aerofoils, also known as stators or vanes, decelerate and redirect the flow direction of the working fluid to the rotating aerofoils of the next stage. In this manner, the compressor produces a continuous flow of compressed working fluid for subsequent combustion and expansion to produce work.
Various devices exist to test the operational performance of compressors. For example, U.S. Pat. No. 6,220,086 describes a method and apparatus for testing the surge pressure ratio in compressors for turbines. The apparatus includes ducting that supplies the working fluid to the compressor inlet through a throttle valve. The position of the throttle valve is temporarily changed to briefly decrease the flow of working fluid into the compressor inlet during the testing.
The test device described in U.S. Pat. No. 6,220,086 does not include the ability to accurately measure the flow of working fluid into the compressor inlet. In addition, the test device does not include the ability to control the temperature of the working fluid prior to entry into the compressor inlet. Therefore, if the transient change in the flow of working fluid is not sufficient to perform the desired test, the process must be repeated, and the throttle valve must be temporarily changed to further briefly decrease the flow of working fluid into the compressor inlet to perform the desired test. Therefore, the test device may require a repetitive process to determine the correct throttle position to sufficiently reduce the flow of working fluid into the compressor inlet to perform the desired test.
Therefore, the need exists for a test device that can accurately deliver a desired flow of working fluid to a compressor for testing. In addition, the need exists for a test device that can increase the temperature of the working fluid prior to entry into the compressor inlet.